The acquisition was a home run. Today, Instagram would cost Facebook a much great percentage of its market cap than it did in April (about 1%).

Zuckerberg also discussed Facebook's plans for Instagram. It sounds like he wants to keep it pretty independent, similar to the way Google handled YouTube.

"We want to help it grow to hundreds of millions of users. We have no agenda into making them going into our infrastructure. We're going to do the things we would have done if they were an Open Graph partner, but we'll be able to prioritize them."